Analyte detection in physiological fluids, e.g. blood or blood-derived products, is of ever increasing importance to today's society. Analyte detection assays find use in a variety of applications, including clinical laboratory testing, home testing, etc., where the results of such testing play a prominent role in diagnosis and management in a variety of disease conditions. Analytes of interest include glucose for diabetes management, cholesterol, and the like. In response to this growing importance of analyte detection, a variety of analyte detection protocols and devices for both clinical and home use have been developed.
One type of system that allows people to conveniently monitor their blood glucose levels includes a sensor (e.g., a disposable test strip), for receiving a blood sample from a user, and a meter that delivers an electrical impulse to the test strip and collects data during an electrochemical reaction to determine the glucose level in the blood sample. The test strip typically includes an electrical contact area at one end for electrically communicating with the meter and a sample chamber at the other end that contains reagents (e.g., glucose oxidase and a mediator) and electrodes. To begin the test, one end of the test strip is inserted into the meter and the user applies a blood sample to the sample chamber at the other end of the test strip. The meter then applies a voltage to the electrodes to cause a redox reaction and the meter measures the resulting current and calculates the glucose level based on the current. After the test, the test strip can be disposed.
It should be emphasized that frequent measurements of blood glucose levels may be critical to the long-term health of many users. As a result, there is a need for blood glucose measuring systems that are easy to use. However, as sample sizes become smaller, the dimensions of the sample chamber and electrodes in the test strip also become smaller. This, in turn, may make test strips become more difficult to handle.
One solution has been the use of cassettes that hold a series of test strips (e.g., a dozen) that can be mechanically fed into a meter without handling by a user. For example, one such cassette has a circular configuration with axially positioned test strips. Through a complicated mechanized procedure, the cassette is rotated into position and a test strip is fed into the meter. Unfortunately, such systems can require complex mechanical structures that result in added expense and unwanted bulk.
Accordingly, there is a need to provide blood glucose measuring systems and methods with features for measuring blood glucose levels conveniently and reliably, and in particular, a need for test strips that can facilitate such testing.